The ATLAS experiment has performed measurements of the $CP$-violation phase $\phi_s$ and other physics parameters describing $B_s$ mixing in the $B_s^0\rightarrow J/\psi(\mu^+\mu^-)\phi(K^+ K^-)$ channel using data collected by the ATLAS detector from 13 TeV $pp$ collisions at the LHC with integrated luminosity of 80.5 $\mathrm{fb^{-1}}$. The values measured from 13 TeV $pp$ collisions are then combined with those from 19.2 $\mathrm{fb^{-1}}$ of 7 TeV and 8 TeV data. All measurements are in agreement with the Standard Model predictions as well as with other LHC measurements.